The old saying of a chain is only as strong as its weakest link stands true in machine vision applications. A machine vision hardware solution typically consists of a camera, lens, and light to obtain an image for processing. If anyone of these components are improperly selected, its the weakest. Lighting is a key component to produce features and contrast for image processing. Uniformity, brightness, wavelength and specific geometries used in conjunction with each other are key elements to a good lighting component. In this blog, we introduce Phlox machine vision lighting, which is unsurpassed in uniformity and has many key advantages.
Phlox lighting provided much more than just lighting, regardless of the application. Below are 5 main attributes making Phlox unique
1 – Better uniformity: A precise mathematical model and the micro prisms (< 30 µ) enable us to reach up to +/- 5 % uniformity for the backlight surface.
2 – Higher luminance: Up to 80% of the light injected is emitted onto the target surface, up to twice as much as light pipes using diffusion.
3 – More compact design: Phlox technology is well suited to the manufacture of very thin pipes (1 mm). This feature enables Phlox to create very low profile (very thin) products in response to the need to reduce bulk for various applications.
4 – Long life cycle: The combination of Phlox technology and the quality of the designs ensures constant control of temperature and provides an exceptional life cycle.
5 – Faster response: Fast delivery of a standard products and five (5) weeks on average to design and delivery of a prototype or custom-made product.
How do Phlox back lights compare to the competition?
The following are application examples showing the increased contrast generated by Phlox back lights:
In conjunction with the unparalleled uniformity, Phlox lighting can be configured with a variety of wavelengths optimizing contrast as seen in the examples below.
Phlox uses exclusive technology, providing many key advantages along with a 2-year warranty
1stVision is the exclusive distributor in North America for Phlox product. Contact us to discuss your application with our experienced technical advisors – CLICK HERE
1st Vision’s sales engineers have an average of 20 years experience to assist in your camera selection. Representing the largest portfolio of industry leading brands in imaging components, we can help you design the optimal vision solution for your application.
Pulsing (aka strobing) a machine vision LED lightis powerful technique that can beneficial to machine vision systems in various ways.
This blog post outlines 5 benefits you will receive from pulsing a LED light head. Gardasoft is an industry leader in strobe controllers capable of driving 3rd party LED light heads or custom LED banks for machine vision.
1 – Increase the LED light output
It is common to use pulsed light to “freeze” motion for high speed inspection. But, when the light is on only a short term in burst, its possible to increase the light output beyond the LED manufacturers specified maximum, using a technique called “Overdrive”. In many cases, the LED can be powered by 10X over the constant current power input in turn providing brighter pulses of light. When synchronized with the camera acquisition, a brighter scene is generated.
2 – Extend the life of the LED
As mentioned in the first benefit, strobing a LED light head only turns on the LED for short period of time. In many cases, the duty cycles are very low which extends the life of the LED and any degradation in turn, keeping the scene at a consistent brightness for years. (i.e. If the duty cycle is only 10%, the lifetime of the LED head will increase by 10%)
3 – Ambient Light control
Ambient light conditions frequently interfere with machine vision measurements and these issues can be solved by pulsing and over driving the system’s LEDs. For example, over driving the LED by 200% doubles the light intensity and enables the camera exposure to be halved, so reducing the effects of ambient light by a factor of 4. The end result is the cameras exposure is only utilizing light from the give LED source and NOT ambient light.
4 – High speed imaging and Increased depth of field
Motion blur in images from fast-moving objects can be eliminated with appropriate pulsing of the light. In some cases a defined camera exposure will be good enough to freeze motion (read our blog on calculating camera exposure), but may suffer in light intensity with constant illumination. “Over driving” a light can boost the output up to 10x its brightness rating in short pulses. Increased brightness could allow the whole system to be run faster because of the reduced exposure times. Higher light output may also allow the aperture to be reduced to give better depth of field.
Gardasoft controllers include our patented SafePower™ and SafeSense™ technology which prevents over driving from damaging the light.
5 -Multi-Lighting schemed & Computational Imaging
Lighting controllers can be used to reduce the number of camera stations. Several lights are set up at a single camera station and pulsed at different intensities and duration’s in a predefined sequence.
Each different lighting can highlight particular features in the image. Multiple measurements can be made at a single camera station instead of needing multiple stations and reduces, mechanical complexity saving money. For example, sequentially triggering 3 different types of lighting could allow a single camera to acquire specific images for bar code reading, surface defect inspection and a dimensional check in rapid succession.
Pulsed multiple lighting schemes can also benefit line scan imaging by using different illumination sources to capture alternate lines. Individual images for each illumination source are then easily extracted using image processing software.
In conclusion, strobe controllers can provide many benefits and save money in an overall setup more than the cost of a controller!
Advanced Illuminationhas reduced pricing on their EuroBright lighting product line. This IP67 lighting line provides the highest levels of strobed or continuous operation using “FlexTech” technology and does not require additional controllers.
FlexTech™ is Advanced Illumination’s exclusive technology collection which they have spent years perfecting. This consists of self-sustaining technologies for your system protection and your peace of mind.
The EuroBright Series consists of 6 styles of illuminator’s providing various lighting geometries from area illumination to back lighting. Each light style can be ordered in various wavelengths and has self contained electronics allowing continuous or strobe operation. EuroBright Illuminators are feature rich with the following key features:
Low cost, feature-rich design
Robust IP67 enclosures
On-board smart driver – seamlessly provides strobe or continuous operation
Adaptive Overdrive – Optimized power under all strobe conditions
In essence, FlexTech technology maximizes intensity even in varied temperature conditions ensuring the illuminator is providing maximum performance and protected. You do not have to worry about over driving the light source.. FlexTech does this for you! What benefits does FlexTechnology bring to EuroBright Illuminators? Adaptive Overdrive
Adaptive Overdrive™ shapes the output pulse of the illuminator to maximize the intensity seen in the image. This technology allows for a very flexible on-board driver where the output is always performing at its peak with any camera exposures.
Adaptive Power allows for the user to “train” the light to operate in varied external temperatures. This was designed primarily for the EuroBrite™ Series of lights. Training allows the controller to identify the correct operational current such that the light does not overheat. Adaptive Power guarantees maximum brightness and lifetime regardless of the installation.
Smart Power Allocation
Smart Power Allocation performs load-balancing to be sure each individual channel on a controller is always being utilized to its fullest. Rather than relying on a fixed “current” for a light, factors such as voltage and string combination are considered in determining the correct operating range. Standard products have up to a 30% higher output with this feature enabled.
Packed with features, EuroBright illuminators are one of the most advanced lights on the market for a great price!
A successful, cost-effective application of a Machine Vision system is often dependent on the interplay of many individual elements, including machine vision lighting. As much as an Light Emitting Diode (LED) appears to be a basic electronic component, driving it in a fashion suitable for machine vision applications is non-trivial. LED’s have become the staple in industrial imaging applications in which consistent illumination is key. In order to achieve constant illumination and synchronization with cameras, controllers from Gardasoft should be utilized. Download the full white paper here NOW
Why use a LED Lighting Controller? LED Light Controllers are an essential element of any vision system which needs to optimize illumination intensity and precision trigger sequencing between vision cameras and lights. The following are the main areas where you will benefit from the use of an LED light controller: Pulse (or strobe) control Where you need to synchronize the ON time of your light with the camera and target product (controllers are available for nano-second timing resolution) Overdriving Where you require increased intensity from your LED light for a short, defined, period of time (with up to 10x over driving capability) Continuous current power supply (constant light) Where you require a highly stable constant current supply for constant on LED lighting Control of multi-lighting schemes For systems with multiple lighting configurations which require intensity control and high speed synchronization (from single or multiple triggers) Remote configuration changes For systems where it is advantageous to have remote setting of lighting system parameters – eg: to facilitate efficient set-up during system commissioning
LED Technology Overview LEDs are current driven devices. While LED Lights are specified as either 12V or 24V lights, the actual LEDs are semiconductor devices whose light output is a direct result of the current through the device, not the voltage. All LED device manufacturers specify that current control is advised for efficient use. Typically, LED datasheets will indicate that very small changes in LED voltage results in large changes in the LED current; and large changes in LED current results in large changes in light output intensity. As seen in the diagram to the right, small changes in forward voltage (Vf),greatly change current ( If ) Gardasoft LED controllers regulate the current, not the voltage, so that light output is stable, tightly controlled and highly repeatable. Controlling the current allows for precise control of the LED light output, with an additional benefit to users looking to overdrive their lights to increase light output. There are many advantages of accurate pulsing and over driving LED’s. However it is also extremely important to ensure LEDs are over driven safely to ensure long life and not catastrophic failure. In this white paper, the following topics are covered:
An overview of LED technology
How to pulse and overdrive LEDs safely using Gardasoft’s patented “SafeSense” technology
Three trigger modes from constant, pulses and switched for various applications.
How “SafeSense” technology determines the optimum current for consistent LED drive.
Advanced and custom controller functions. Example – allowing multiple pulses at different intensity levels over various LED channels.